The present disclosure relates to methods for converting light glycol streams of biological origin into products suitable for use as oxygenated fuel additives. These methods involve the acidic condensation of light glycols to form larger products, termed low molecular weight poly-glycols. The remaining hydroxyl functional groups of the poly-glycol products are then modified to decrease the overall polarity of the products, and improve their suitability for use as an oxygenated fuel additive.